Fuzzy Logic Controller in VHDL

The Problems are:

Error (10884): VHDL error at fuzzy_rulebase.vhd(471): cannot access 'internal_control_pl' from inside pure function 'check'.

Error (10884): VHDL error at fuzzy_rulebase.vhd(472): cannot access 'internal_control_pm' from inside pure function 'check'.

Error (10884): VHDL error at fuzzy_rulebase.vhd(473): cannot access 'internal_control_ps' from inside pure function 'check'.

Error (10884): VHDL error at fuzzy_rulebase.vhd(474): cannot access 'internal_control_z' from inside pure function 'check'.

Error (10884): VHDL error at fuzzy_rulebase.vhd(475): cannot access 'internal_control_ns' from inside pure function 'check'.

Error (10884): VHDL error at fuzzy_rulebase.vhd(476): cannot access 'internal_control_nm' from inside pure function 'check'.

Error (10884): VHDL error at fuzzy_rulebase.vhd(477): cannot access 'internal_control_nl' from inside pure function 'check'.

I am a novice recently downloaded test this code.

I tried this code and appear that same messages,too.

Is the fuzzy_rulebase parameters no give values?

I cannot understand.

Thanks